3HDD:
reference: Engrailed homeodomain-DNA complex at 2.2 A resolution: a detailed view of the interface and comparison with other engrailed structures., Fraenkel E, Rould MA, Chambers KA, Pabo CO, J Mol Biol 1998 Nov 27;284(2):351-61. PMID: 9813123

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).